scispace - formally typeset
Search or ask a question
Author

P Jana

Bio: P Jana is an academic researcher. The author has contributed to research in topics: Thermionic emission & Schottky barrier. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: In this article, Wang et al. measured temperature dependent current and series resistance values on palladium-ZnO-Schottky barrier diodes in the temperature range 303?383 K.
Abstract: Zinc oxide (ZnO) nanowire based Schottky barrier diodes are fabricated by depositing Pd metal contact on top of vertically well-aligned ZnO nanowire arrays. A vertical array of ZnO nanowires on indium tin oxide (ITO) coated glass substrates is synthesized by hybrid wet chemical route. Scanning electron microscopy (SEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) measurement confirm the formation of stoichiometric well-aligned hexagonal (h-ZnO) nanowire arrays with wurtzite structure. Temperature dependent current?voltage (I?V) measurements on palladium-ZnO (Pd/ZnO) nanowire Schottky junctions in the temperature range 303?383 K exhibit excellent rectifying character. From these nonlinear I?V plots, different electrical parameters of diode-like reverse saturation current, barrier height and ideality factor are determined as a function of temperature assuming pure thermionic emission model. The ideality factor is found to decrease while the barrier height increases with the increase in temperature. The series resistance values calculated from Cheung?s functions also show temperature dependency. Such behavior can be attributed to the presence of defects that traps carriers, and barrier height inhomogeneity at the interface of the barrier junction. After barrier height inhomogeneity correction, considering a Gaussian distributed barrier height fluctuation across the Pd/ZnO interface, the estimated values of mean barrier height and modified Richardson constant are more closely matched to the theoretically predicted value for Pd/ZnO Schottky barrier diodes. The variation of density of interface states as a function of interface state energy is also calculated.

15 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: Solution-processed ZnO Schottky diodes based on a coplanar Al/ZnO/Au nanogap architecture are reported on and the nature of the rectifying contact formed at the ZnNO/ au interface is studied.
Abstract: Much work has been carried out in recent years in fabricating and studying the Schottky contact formed between various metals and the n-type wide bandgap semiconductor zinc oxide (ZnO). In spite of significant progress, reliable formation of such technologically interesting contacts remains a challenge. Here, we report on solution-processed ZnO Schottky diodes based on a coplanar Al/ZnO/Au nanogap architecture and study the nature of the rectifying contact formed at the ZnO/Au interface. Resultant diodes exhibit excellent operating characteristics, including low-operating voltages (±2.5 V) and exceptionally high current rectification ratios of >106 that can be independently tuned via scaling of the nanogap’s width. The barrier height for electron injection responsible for the rectifying behavior is studied using current–voltage–temperature and capacitance–voltage measurements (C–V) yielding values in the range of 0.54–0.89 eV. C–V measurements also show that electron traps present at the Au/ZnO interface ...

45 citations

Journal ArticleDOI
TL;DR: In this paper, a well-aligned n-ZnO nanowire (NW) thin films were deposited onto p-Si substrates by a two-step wet chemical technique to form a p-n heterojunction diode.
Abstract: Vertically well-aligned n-ZnO nanowire (NW) thin films were deposited onto p-Si substrates by a two-step wet chemical technique to form a p–n heterojunction diode. The morphological and structural characteristics of the ZnO NW performed by scanning electron microscopy (SEM) and x-ray diffraction (XRD) revealed well-aligned h-ZnO NW with a wurtzite structure. A direct optical band gap of 3.30 eV was calculated from the transmittance trace obtained using a UV–VIS–NIR spectrophotometer. The electrical characteristics of the heterojunction diode were studied by capacitance–voltage (C–V) measurement at room temperature, and current–voltage–temperature (I–V–T) measurements performed in the 300–400 K range. The C–V measurements yield a carrier concentration of 1.3 × 1016 c.c.−1 for the ZnO NW thin film. The ideality factor (n) was found to decrease, while the barrier height ( b0) increased with the increase in temperature, when calculated using a thermionic emission model from the non-linear I–V–T plots. The series resistance (R s) calculated by the Cheung–Cheung method decreased with the increase in temperature. The mean barrier height (0.718 eV) and modified Richardson constant (28.4 A cm−2 K−2) calculated using a Gaussian distribution of barrier heights (considering barrier height inhomogeneity) were closer to the theoretical value than those calculated from the linear approximation of the ln(I s/T 2) versus 1000/T plot. The variation of the density of interface states with interface state energy was also studied. The n-ZnO NW/p-Si heterojunction diode performed very good half wave rectification in the frequency range 50 Hz–10 kHz, when a sinusoidal ac voltage of amplitude 4.5 V was applied across it.

28 citations

Journal ArticleDOI
TL;DR: Cheung et al. as mentioned in this paper used spray-coated ZnO and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) to produce multiparametric UV-photodetectors.

24 citations

Journal ArticleDOI
TL;DR: In this article, the electrical characterization of p-Silicon (Si) and n-Zinc oxide (ZnO) nanorod heterojunction diode has been performed.
Abstract: The electrical characterization of p-Silicon (Si) and n-Zinc oxide (ZnO) nanorod heterojunction diode has been performed. ZnO nanorods were grown on p-Silicon substrate by the aqueous chemical growth (ACG) method. The SEM image revealed high density, vertically aligned hexagonal ZnO nanorods with an average height of about 1.2 μm. Electrical characterization of n-ZnO nanorods/p-Si heterojunction diode was done by current-voltage (I-V), capacitance-voltage (C-V), and conductance-voltage (G-V) measurements at room temperature. The heterojunction exhibited good electrical characteristics with diode-like rectifying behaviour with an ideality factor of 2.7, rectification factor of 52, and barrier height of 0.7 V. Energy band (EB) structure has been studied to investigate the factors responsible for small rectification factor. In order to investigate nonidealities, series resistance and distribution of interface state density (NSS) below the conduction band (CB) were extracted with the help of I-V and C-V and G-V measurements. The series resistances were found to be 0.70, 0.73, and 0.75 KΩ, and density distribution interface states from 8.38 × 1012 to 5.83 × 1011 eV−1 cm−2 were obtained from 0.01 eV to 0.55 eV below the conduction band.

22 citations

Journal ArticleDOI
TL;DR: In this paper, a transparent composite film of graphene oxide (GO) and zinc oxide (ZnO) was constructed by all-solution process and the nonlinear current-voltage characteristics at room temperature resemble Schottky barrier junction formation between ZnO-GO film surface and Ag dot.

22 citations